Bydgoszcz is a city in northern Poland, straddling the confluence of the Vistula River and its left-bank tributary, the Brda. With a city population of 339,053 as of December 2021 and an urban agglomeration with more than 470,000 inhabitants, Bydgoszcz is the eighth-largest city in Poland. It is the seat of Bydgoszcz County and the co-capital, with Toruń, of the Kuyavian-Pomeranian Voivodeship.

The Vistula is the longest river in Poland and the ninth-longest in Europe, at 1,047 kilometres in length. Its drainage basin, extending into three other countries apart from Poland, covers 193,960 km2 (74,890 sq mi), of which 168,868 km2 (65,200 sq mi) is in Poland.